Switch



Oct. 27,l 1.942.A w. v. HONEY ASWITCH I 'Fed march -11,I 1941 .3Shawna-Sheet` 1 F@ 5. .rz ff (EJIllllllllllllllllllll'lllllllhmInventor: WllllamV l-Iohex l)by .X7/Md.

His Attorney loef. 27, 1942.1

w. v. Hom-:Y

swncn Filed March 11, 1941 s sheets-sheet? Inventor: Wil-Ham V Hong. v bJVM 6J s His Attor'ne'y.

Oct. 27, 1942.

SWITCH 'v v Filed uar'cn 11, 194x 3 Sheets-Sheet 3 Inventor: WilliamHohe 2 His Attorney Patented Oct. 27, 1942 SWITCH William V. Honey,Fortress Monroe, Va., assigner to General Electric Company, acorporation of New York Application March 11, 1941, Serial No. 382,795

(Cl. 20G-1!) 22 Claims.

My invention relates to electric switches, and although not limitedthereto, it has application to a hand-operated motor starting andreversing switch.

An object of my invention is to provide an improved switch which willhave long life, be easy to operate, and which will have suchconstruction as to facilitate assembly thereof.

Another object of my invention is to provide an improved switchconstruction of the abovementioned type which will have a minimum ofsize for a maximum current carrying capacity of its contacts.

A further object of my invention is to provide a switch structure withan improved contact design so as to minimize bouncing and to provide fora rolling action between the contacts when they are being moved intoengagement.

A still further object of my invention is to provide an improvedlatching mechanism for a switch for holding the actuating mechanismthereof in a predetermined position.

A still further object of my invention is to provide an improved lockingmechanism for a switch for controlling the direction of movement of theactuating mechanism thereof.

My invention will -be more fully set forth in the following descriptionreferring to the accompanying drawings, and the features of noveltywhich characterize my invention will be pointed out in the claimsannexed to and forming a part of this specication.

In the drawings, Fig. 1 is a front view of a double-pole double-throwswitch the cover having been partly broken away, which is provided withan embodiment of my invention; Fig. 2 is a side elevation in partialsection of the switch illustrated in Fig. l; Fig. 3 is a top View, withthe top part of the casing broken away of the switch illustrated inFigs. l and 2; Fig. 4 is a skeleton perspective view of the currentcarrying members of the switch illustrated. in Figs. l to 3; Fig. 5 isan enlarged view of one of the pairs of contacts and a portion of theoperating mechanism thereof, of the switch illustrated in Figs. 1 to 3,the switch contacts being in open circuit position; Fig. 6 is a View ofthe pair of contacts illustrated in Fig. 5 in a fully closed position;Fig. '7 is a perspective view of two movf" able contacts and a portionof the operating mechanism thereof, of the switch illustrated in Figs. 1to 3; Figs. 8. 9 and 10 are enlarged side elevations of the locking andlatching mechanism employed in the switch illustrated in Figs. 1 to 553, the mechanism being shown in a neutral position, in one or a reverseposition, and in a second or a forward position, respectively, and Fig.11 is a perspective View of the locking mechanism illustrated in Figs.8, 9, and 10.

The switch illustrated in the drawings is a hand-operated motor startingand reversing switch. However, it is to be understood that the improvedfeatures of my switch construction may be employed in any other suitabletype of switch. The illustrated switch construction includes a pluralityof pairs of relatively movable contacts, and an actuating mechanismmovable in one direction for closing two pairs of the contacts which mayconnect the motor across a suitable source of supply to operate themotor in a forward direction, the operating mechanism being movable in asecond direction to close the other two pairs of contacts in order tooperate the motor in a reverse direction. The operating mechanismincludes a contact supporting arm or cross bar upon each end of which ispivotally mounted one of the relatively movable contacts. A contact tiphaving an arcuate shaped Contact surface extends from one side of thepivot, and the other end is adapted to provide a stop for the contact.Between the stop and the pivot there is provided a spring means forbiasing the stop end of the contact into engagement with the supportingarm. Upon movement 'of the actuating mechanism the supporting arm andcontact will bodily move until an initial point of engagement obtainsbetween the relatively movable contacts. Further movement of theactuating mechanism will cause the movable tip to roll on the stationarycontact until a iinal position of engagement is obtained, the contactpressure being provided through the spring means. The movable contact isheld in this latter position by a latching mechanism which cooperateswith the operating means. I also provide a locking mechanism whichincludes a pair of dogs and a locking plate, which when in one positionprevents the operating arrangement from being moved in one direction, orin a direction to reverse the operation of the motor, but allow movementof the operating mechanism to close the contacts to rotate the motor inthe forward direction. However, upon movement of the locking mechanismto a second position, by any suitable means, such as a key, theactuating mechanism will be allowed to move into a reverse position andat the same time be prevented from moving into a forward position untilthe locking mechanism is again returned to a neutral or iirst position.

I may also provide improved busbars with slots in the ends thereof formaking connection between a pair of relatively stationary perpendicularconnecting posts. Thus, by loosening nuts on the posts, the busbars maybe removed from the bolts through the slots thereof.

Referring more particularly to Figs. l, 2, and 3, the switchconstruction shown includes a box or enclosing casing 2D, a removablecover 2|, and a removable dish shape container or oil tank 22, which maybe lled with oil if it is desired to have the switch contacts operate ina fluid insulating medium. Thetank 22 is tightly held in a U-shapeflange 23 of the enclosing casing in any suitable manner, such as bymeans of a plurality of bolts and wing nuts 24. A conduit box 25 isprovided which may be bolted to the casing 20 through a plurality ofbolts 25. The conduit box 25 may in turn be bolted to any suitablesupport, such as a wall, which will in turn support the entire switchconstruction. An aperture 21 is provided through which lines or conduitsmay pass for connecting my improved switch construction with anysuitable electric device, such as a dynamoelec tric machine. The conduitbox 25 is provided with an insulating plate 28 and any suitable numberof busbar studs. Since this switch construction is to be employed as adouble-pole double-throw switch, four studs 29, 30, 3|, and 32 areprovided. Studs 3| and 32 may be connected to a suitable source of powerand 29 and 30 to a suitable device, such as a motor. The studs 29, 3U,3|, and 32 also are connected to busbars 33, 34, 35, and 35,respectively. The opposite ends of these busbars are adapted to makeelectrical connection with four contact studs 31, 38, 39 and 40respectively, which are in turn connected to my improved contactstructure which will be described below. Since the busbar studs andcontact studs, which are connected together by busbars, areperpendicular to each other, I provide the ends of each of the busbarswith U-shaped slots so that the busbars may be conveniently removed bymerely loosening the locknuts on each of the studs which are adapted tohold the busbars tightly on the studs. It may also be seen that byremoving the two busbars i which are connected to the source of powerthe switch may be isolated therefrom in a simple and a convenientmanner.

In order to provide a relatively stationary support for the contactstructure, a base or supporti..

ing plate 4| of insulating material is placed within the enclosingcasing and is stationarily mounted thereon through inwardly extendingribs 42, bolts 43 being provided for tightly securing the base 4| to theribs. Attached to the base 4|, I may provide any suitable number oistationary contact studs. Since this switch is employed with adouble-pole double-throw switch, four stationary contact posts areprovided. rIhese include the studs 31 and 33 and studs 44 and 45. Thesefour contact posts 31, 38, 44, and 45 have relatively stationarycontacts 46, 41, 48, and 49, respectively, mounted thereon in anysuitable manner, such as by bolts 5i) which extend into cooperatingthreaded holes in the studs. Adapted to cooperate with these relativelystationary contacts, I provide relatively movable contacts 5|, 52, 53,and 54. Thus, there are provided four pairs of relatively movablecooperating contacts. Contacts 5| and 53 are each connected to the studthrough a pigtail 55, and relatively movable contacts 52 and 54 are eachconnected to the stud 39 through a pigtail 55. These connections may bemade in any suitable manner, and in the illustrated construction the twosimilar pigtails each have their mid-points connected to the studs andtheir ends connected to the contacts through bolts 51, see Fig. '1.Reversing busbars 58 and 59 are connected between studs 31 and and 38and 44, respectively. The connection between the studs and bars may bemade in any suitable manner, suoli as by bolts G9.

The electrical connections may be traced in the skeleton viewillustrated in Fig. fi. Assuming that the studs 3| and 32 are connectedto a suitable source of supply and that the studs 29 and 35 areconnected to a motor. the circuit may be traced from the stud 3| throughthe busbar 35 to the center stud 33. Let us iurther assume that theContact operating mechanisin, which will be described below, has been sooperated that the motor is to be run in a forward direction. Thus,contacts 49 and 54, and 4B and 53 are respectively in circuit closingposition. The center stud 39 is, therefore, connected through thepigtail 55 to contact 54 which contacts the stationary contact 49. Thiscontact is in turn connected through the busbar 58 to the stud 31 whichis in turn connected through the busbar 33 to the outgoing stud 29. Theother circuit may be similarly traced from the stud 32, busbar 36, studliil, pigtail 55, contacts 53, 48, busbar 53. stud 33, busbar 34 to thestud 30. It may be seen that when the contact operating mechanism ismoved so that contacts 46, 5|, and 41, 52 are moved to circuit closingpositions that the current will be reversed through the motor.

The operating mechanism for the movable contacts includes a plurality ofcontact supporting arms or cross bars 6 Since a relatively movablecontact may be pivotally mounted at each end of the supporting arms onlytwo need be provided in order to support four movable contacts.

However, it is to be understood that any other suitable number ofcontact supporting arms may be provided, depending upon the number ofpairs of contacts which the switch need employ, and, if desired, onlyone movable contact need be mounted on each supporting arm. The movablecontacts may be movably mounted on their supporting arms in any suitablemanner, and in the illustrated embodiment of my invention I provideknife edge pivots 62 at each of the ends of the arms. Since each of themovable contacts are similarly mounted only the mountings of one will bedescribed, such as that of contact 54. Referring more particularly toFigs. 5, 6, and 7 it will be seen that a V-shape indentation 63 isprovided in the lower side of the contact in order to cooperate with theknife edge pivot 62. The contact is provided with a suitable arcuateshape contact tip surface 64 which is adapted to make rolling contactwith the surface of the cooperating stationary contact. The contact endhaving the tip 64 extends on one side of the pivot while the oppositeend of the contact is provided with a stop portion 65 which is adaptedto overlie a cooperating portion 56 of the Contact supporting plate. Thepart of the arm 4between the pivot and the portion 6G is undercut at 61,so that the contact will not touch the arm between these points.Operatively connected to the contact supporting arm and the contact, andbetween the stop 65 and the pivot 63, I provide a suitable biasingarrangement which includes a spring 68 which is compressed between aportion of a sur- -face 69 on the opposite side of the conta-ctsupporting arm from the pivot 62 and a dish shape member 16 which is inturn supported by a spring rod 1|. Aligned apertures 12 and 13 areprovided in the contact and the contact supporting plate, respectively,and a T-shape end 14 of the spring supporting rod 1| spans the aperture12 while the opposite end 15 of the spring supporting rod supports thedish shape member 10. It will be seen, therefore, that the movable-contact 54 is biased towards the contact supporting arm 6| by thespring means 68. The other movable contacts are similarly mounted. Thesecontacts are easily removable by removing the screws 51 and pushing upon the spring 68 and rotating the rod 1|, 90 degrees so as to allow theend 14 to drop through the apertures 12 and 13.

In order to support the contact supporting arm or cross bar, there isprovided a shaft 16, which may be covered by any suitable type ofinsulating material 11, the shaft being rotatably mounted at its ends inbearings 18, one being shown in Fig. 1. The bearings 1B are in turnsupported through a bearing bracket 19 from the lower side of the baseplate 4|. Suitable bolts 88 connect the bearing 18 to one end of thebracket while suitable bolts 8| connect the opposite end 'of the bracketto the lower surface of the plate 4|. The contact supporting arm 6| ismounted on the shaft 16 in any suitable manner, such as by providing aplate member 82 below the shaft and by tightly securing the plate 82 tothe opposite side of the shaft from the contact supporting arm 6| by anysuitable number of bolts 83 which extend from the plate 82 intocooperating holes in the Contact supporting arm 6|. It may be seen,therefore, that the contact supporting arm is pivotally mounted at itsmid-point on an axis which is perpendicular to its longitudinal axis.Each of the contact supporting arms 6| may be similarly mounted on theshaft 16.

Another part of the contact actuating mechlanism includes a contactpositioning or rocker arm 84, see Fig. 1 or Figs. 8, 9, and 10, whichhas one end tightly secured to the shaft 16, in any suitable manner,such as by a pin 85. The opposite end of the contact positioning arm isprovided with a pin 86 which extends from one face thereof. The pin 86is in turn adapted to be moved or operated by a contact operating arm 81which has a slot 88, see Figs. 8, 9 and 10, which is adapted to receivethe pin 86. The operating arm 81 is vrotatably mounted in the enclosingc-asing 29 through a shaft 89 which extends through a suitable hole oris accommodated by a suitable bearing supported by the enclosing casing26. The operating arm 81 is also provided with an extension 99 which isadapted to coopate with my improved locking mechanism, which will bedescribed hereinafter. The outside end of the shaft 89 is provided withany suitable operating arrangement, such as a handle 9| so that theswitch may be manually operated. It is to be understood that the shaftmay be automatically operated, if desired.

It will be seen, therefore, that when the handle as viewed in Fig. 1 ispushed away from you, or as viewed in Fig. 2 is rotated clockwise, thecontact positioning or rocker arm 84 as viewed in Figs. 5 and 6 will becaused to rotate around the shaft 16 in a counterclockwise direction.Movement of a sufcient amount will cause the conlli tacts 54 and 49 tomove from the position as illustrated in Fig. 5 to the fully closedposition illustrated in Fig. 6. When the operating handle is moved inthe opposite direction the switch parts will move from the neutralposition as shown in Fig. 5 to a reverse position or with the contacts5|, 46, and 52, 41 in contact.

In order to provide an arrangement for latching the operating mechanismin a neutral, or in -a forward, or in a reverse position, I provide alatching mechanism which includes a latching -arm 92 which is pivotallymounted on a bracket 93 which is in turn supported by the plate 4|. Thelatching arm 92 is provided with a roller -94 which is adapted tocooperate with any one of three notches 95, 96, and 91 on the contactpositioning arm 84, since the latching plate is biased towards thecontact positioning arm through a spring 98. Therefore, by means of thislatching mechanism the contact mechanism will also be held in a stablemanner in a neutral, or in a forward, or reverse position, the neutral'position being shown in Figs. 5 and 8, the forward position in Figs. 6and 10, and the reverse position in Fig. 9.

It will, therefore, be seen that with the contact construction asdescribed above that a maximum of wipe and wear allowance will beobtained. Referring again to Fig. 5, contacts 54 and 49 are adapted tomake initial engagement at any suitable .point such as the points markeda and b. Furthermore, by suitably proportioning the curve of the arcuateshape tip 64 and the position of the pivot point 62 with respect to thecenter of rotation of the shaft 16 and the tip, the contacts uponfurther movement after the points a and b touch, may be made to roll andhave substantially no slide therebetween. Thus, after the contacts havetouched at the points a and b further movement of the actuatingmechanism will cause relative movement between the contact 54 and thecontact supporting arm 6| around the pivot points 62 and 63, against theforce of the biasing means 68. This movement will continue until thecontacts 54 and 49 have reached the position as illustrated in Fig. 6,or until points c and d are in engagement, at which time the roller 54of the latching mechanism will have dropped into the slot 91 to securelyhold the contacts in this position, until the roll 94 is forced out ofthe slot 91 against the force of the biasing spring 98 by the operatorstriking a blow on the operating arm 92. In order to minimize thepossibility of bouncing as the contacts touch when moving to a closedposition, the center of gravity of the contact 54 is at any suitablepoint toward the stop 65 or to the left of the pivot point 62. Switchstructure including a relatively stationary contact, a relativelymovable contact, and a contact member resiliently connected to a movablearm, the contact member being pivotally connected to the arm between thecenter of gravity of the contact member and the relatively movablecontact which is carried by the member so as to prevent bouncing duringclosing of the contacts is described and claimed in an application S. N.420,107, Stimson, led November 22, 1941, and assigned to the sameassignee as this present invention.

In order to provide a contact structure which will have a minimum ofresistance during normal running conditions and to minimize thepossibility of welding during making and breaking, the contact structure54, 49 is provided with silver inserts at the points c and d which areso situated that they will be tightly pushed together at the moment thatthe roll 94 of the latching mechanism drops into the slot 9i. Theremainder of the contact tip 54 and the cooperating surface of thestatic-nary Contact 49 may be made of any suitable contact material,such as that described and claimed in Patent 2,178,598 to Ziclzrick,which is also assigned to the same assignee as this present invention.In the arrangement illustrated only the forward contacts 53, t8, and 54,49 are provided with this silver insert construction. However, it is tobe understood that all the contacts may be so constructed, if desired.All the contacts, however, are mounted so as to produce the wipingaction and minimise bouncing. It is also to be noted that the contactpressure when the contacts are in their fully closed position, asillustrated in Fig. 6, is determined by the biasing spring 68. Thisforce may, therefore, be varied by changing the characteristics of thespring.

In order to prevent any unintentional closing of the contacts 5|, 46 and52, 41, or when my improved switch structure is employed as a startingand reversing switch of a dynamo-electric machine, in order to preventunintentional reversing of the motor, I provide an improved lockingmechanism which is illustrated in Figs. 8 to l1. This locking mechanismincludes a pair of dogs 99 and |00 which are pivotally mounted on thecasing 29 through pins |9| and W2, rcspecfi tively. The dogs 99 and |09are biased in one direction by springs ID3 and |94, respectively. Inorder to control the position of the dogs 99 and |00 I provide a lockingplate |35 which is pivotally mounted in the casing 2B through a pivotpin |96. The dog 99 is provided with a stop surface |07 which is adaptedto cooperate, when in the position as illustrated in Fig. 8, with acooperating surface |t 8 of the extension 9i) of the operating arm 87.Thus, when the dog 99 is in the position as illustrated in Fig. 8 theoperating arm will be prevented from moving in a counterclockwisedirect-ion, or the operating arm will be prevented from moving to asecond position or to a reverse position, which position is illustratedin Fig. 9. The dog 99, however, is operatively connected to the lockingplate |95 through the slot |09 in the locking plate and a pin IG on thedog. The locking plate and dog 99 may be moved from the positionillustrated in Fig. 8 to that illustrated in 9, so that the contacts maybe closed to reverse the motor, in any suitable manner. In thearrangement illustrated in the drawings a suitable key arrangement isprovided having an L-shaped portion which is attached to a shaft i2 anda suitable handle ||3. An aperture H4 is provided in the casing Zi) anda slot ||5 is provided in the locking plate |95 so that when the key isinserted in the aperture M and rotated from the position illustrated inFig. 8 to the position illustrated in Fig. 9 the locking plate |05 willbe rotated around its pivot |96 and through the pin and slot connection|09, |||l the dog 99 will be moved out of the path of movement of theContact operating arm. Suitable stops H6, |l`| and IIB may be providedfor preventing movement of the locking plate and the key beyondpredetermined positions. The dog |00 is provided with a pin H9 whichcooperates with a shoulder |23 on the side of the locking plate oppositefrom that in which the slot |69 is placed. When the locking plate m5 isin the position as illustrated in Fig. 8 the dog |30 will be held out ofthe range of movement of the end of the operating arm El' so that theoperating mechanism may be freely moved from neutral into forwardposition. However, when the locking mechanism is moved so that theactuating mechanism may be moved into reverse position the dog |99 dueto the spring bias |04 will move so that the stop surface |21 isprovided so that the actuating mechanism may not be moved into a forwardposition but may only be moved to a neutral position. lIhe spring |93 ismade stronger than the spring H34 so that when the key is removed thelocking plate |95 may not be accidently moved or jarred into theposition as illustrated in Fig. 9 but will remain in the position asillustrated in Fig. 8, since it will be forced against the stop H5. Itwill be noted that when the key is inserted and rotated to the positionshown in Fig. 9, it cannot be removed until it is returned to theneutral position as shown in Fig. 8. It is to be understood that if itis desired, only one dog need be provided so as to prevent the actuatingmechanism from being moved in one direction but which will not preventit from moving in the opposite direction. Thus, the dog 99 or the dog|99 could be dispensed with in some installations.

In view of the foregoing, it will be seen that I have provided animproved switch construction which includes a contact assembly forproviding a rolling action so that the contacts may make and break atone point of contact and run at a second position. The movable contactis movably mounted in an improved manner so as to minimize thepossibility of bouncing. I also provide an improved latching mechanismfor securely holding the contacts in a neutral, or in a first, or asecond position. An improved locking mechanism is also provided forpreventing movement of the actuating mechanism in one direction when itis in one position, and when in a second position preventing movement ofthe actuating mechanism in a second direction.

I have described my invention as applied to a double-pole double-throwstarting and reversing motor switch. However, it is to be understoodthat any other suitable number of stationary and movable contacts may beprovided, and that the switch construction may be connected in the lineconnecting any other suitable electric device with a source of power oranother device.

Although I have shown and described particular embodiments of myinvention, I do not desire to be limited to the particular embodimentsdescribed, and I intend in the appended claims to cover allmodifications which do not depart from the spirit and scope of myinvention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

l. In a switch, a first pair of relatively movable contacts, a secondpair of relatively movable contacts, means movable from a neutralposition to a first position for actuating said rst pair of contacts andmovable to a second position for actuating said second pair of contacts,latching means cooperable with said actuating means for holding saidactuating means in its neutral or iirst or second positions in order tohold said contacts in a corresponding position, and locking meanscooperable with said actuating means and movable from a rst to a secondposition, said locking means when in its '.Virst position allowing saidactuating means to move from its neutral position to its rst positionbut preventing movement to its second position, said locking means whenin its second position allowing movement of said actuating means fromsaid neutral to its second position but preventing movement to its firstposition.

2. In a switch, a plurality of pairs of relatively movable contacts,means movable from a neutral to a first or to a second position foractuating a first or a second of said pairs of contacts respectively,latching means cooperable with said actuating means for holding saidfirst or said second pair of contacts in a closed position uponactuation by said actuating means, and locking means cooperable withsaid actuating means and movable from a first to a'second position, saidlocking means when in its first position preventing movement of saidactuating means to its second position, said locking means when in itssecond position preventing movement of said actuating means to its firstposition.

3. In a switch, a plurality of pairs of relatively movable contacts,means including a positioning arm movable from a neutral to a first orto a second position for actuating'a first or a second of said pairs ofcontacts respectively, a latching arm biased towards said positioningarm and cooperable therewith for holding said positioning arm in saidneutral or first or second positions in order to hold said pairs ofcontacts in corresponding positions, and locking means cooperable withsaid actuating means and movable from a first to a second position, saidlocking means when in its first position preventing movement of saidactuating means to its second position, said locking means when in itssecond position preventing movement of said actuating means to its firstposition.

4. In a switch, a plurality of relatively stationary contacts, aplurality of relatively movable contacts cooperable therewith, a contactsupporting arm, means for pivotally mounting said relatively movablecontacts on said supporting arm, actuating meansl including saidsupporting arm movable from a neutral to a rst or to a second positionfor actuating a first or a second of said relatively movable contactsrespectively, latching means cooperable with said actuating means forholding said one or another of said movable contacts in a closedposition upon actuation by said actuating means, and locking meanscooperable with said actuating means and movable from a rst to a secondposition, said locking means when in its first position preventingmovement of said actuating means to its second position, said lockingmeans when in its second position preventing movement of said actuatingmeans to its first position.

5. In a switch, a plurality of relatively stationary contacts, aplurality of relatively movable contacts cooperable therewith, a contactsupporting arm, means for pivotally mounting said relatively movablecontacts on said supporting arm, a positioning arm, actuating meansincluding said supporting arm and said positioning arm movable from aneutral to a first or to a second position for actuating a first or asecond of said relatively movable contacts respectively into engagementwith its cooperating stationary contact, a latching arm biased towardssaid positioning arm and cooperable therewith for holding saidpositioning arm in the neutral or first or second positions in order tohold said actuated contacts in engagement, and locking means cooperablewith said actuating means and movable from a first to a second position,said locking means when in its first position preventing movement ofsaid actuating means to its second position, said locking second of saidpairs of contacts respectively,

vlocking means including a rotatably mounted means when in its secondposition preventing movement of said actuating means to its firstposition.

6. In a switch, a plurality of pairs of relatively movable contacts,means movable in a first or a second direction for actuating a nrst or asecond of said pairs of contacts respectively, latching means cooperablewith said actuating means for holding said first or said second pair ofsaid contacts in a closed position upon actuation by said actuatingmeans, and locking means cooperable vvith said actuating means forpreventing movement thereof in one direction when in one position andpreventing movement of said actuating means in a second direction whenin ay second position.

7. In a switch, a plurality of relatively stationary contacts, aplurality of relatively movable contacts cooperable therewith, a contactsupporting arm having knife edge pivots upon which said relativelymovable contacts are mounted, spring means for biasing said relativelymovable contacts tov/'ard said supporting arm, actuating means includingsaid supporting arm movable from a neutral to a first or to a secondposition for actuating a first or a second of said relatively movablecontacts respectively into engagement with its cooperating stationaryContact, said relatively movable contacts upon actuation by saidactuating means into engagement with its cooperating stationary contactbeing movable about said knife pivot so that it will roll from aninitial contact position with its cooperable stationary contact to afinal closed position, latching means for holding said relativelymovable contact in said actuated position, and locking means cooperablewith said actuating means and when in one position preventing movementof said actuating means to its second position and when in a secondposition preventing movement of said actuating means to its firstposition.

8. In a switch, a plurality of pairs of relatively movable contacts,means including a contact operating arm movable from a neutral to afirst or to a second position for actuating a rst or a latching meanscooperable with said actuating means for holding said actuating means inits neutral or first or second position in order to hold said contactsin a corresponding position, a

locking plate and two rotatably mounted dogs cooperable therewith,spring means biasing said dogs into engagement with said plate, saidlock- .I ing means being movable from a first to a second position, oneof said dogs when said locking means is in its first position cooperablewith said operating arm to prevent movement of said actuating means toits second position, the other of said dogs when said locking means isin its sec- 'ond position cooperable with said operating arm to preventmovement of said actuating means to its first position.

9. In a switch, a plurality of pairs of relatively movable contacts,means including a contact yoperating arm movable from a neutral to afirst or to a second position for actuating a first or a second of saidpairs of contacts respectively, a locking means including a rotatablymounted locking-plate and two rotatably mounted dogs cooperabletherewith, spring means biasing said dogs into engagement with saidplate, said locking means being movable from a first to a secondposition, one of said dogs when said locking means is in its firstposition cooperable with said operating arm to prevent movement of saidactuating arm to its second position, the other of said dogs when saidlocking means is in its second position cooperable with said operatingarm to prevent movement ci said actuating means to its rst position.

10. In a switch, a plurality of relatively stationary contacts, aplurality of relatively movable contacts cooperable therewith, a contactsupporting arm having knife edge pivots upon which said relativelymovable contacts are mounted, spring means for biasing said relativelymovable contacts toward said supporting arm, a contact operating arm,actuating means including said supporting arm and said op rating armmovable from a neutral to a first or to a second position for actuatinga nrst or a second of said relatively movable contacts respectively intoengagement with its cooperating stationary contact, said relativelymovable contacts upon actuation by said actuating means into engagementwith its cooperating stationary contact being movable about its knifeedge pivot so that said Contact will roll from an initial engagementposition with its cooperable stationary contact to a final engagementposition, a locking means including a rotatably mounted locking plateand two rotatably mounted dogs cooperable therewith, spring meansbiasing said dogs into engagement with said plate, said locking meansbeing movable from a nrst to a second position, one of said dogs whensaid locking arm means is in its first position cooperable with saidoperating arm to prevent movement of said actuating means to its secondposition, the other of said dogs when said locking means is in itssecond position cooperable with said operating arm to prevent movementof said actuating means to its first position.

11. In a switch, a relatively stationary contact, a relatively movablecontact, a contact supporting arm having a pivot upon which saidrelatively movable contact is mounted, said relatively movable contacthaving a tip with a curved surface cooperable with said stationarycontact on one side of said pivot, spring means on the other side ofsaid pivot for biasing said relatively movable contact toward saidsupporting arm, a rotatable shaft. means for mounting said supportingarm on said shaft, a contact positioning arm connected to said shaft, anoperating arm operatively connected to said positioning arm so that uponmovement thereof said Contact supporting arm will be bodily rotated withsaid shaft, said last-mentioned movement causing relative movementbetween said pivot and said stationary contact to move to said movablecontact into engagement with said stationary contact, continued movementof said supporting arm causing relative movement between said relativelymovable ccntact and supporting arm around said pivot against the forceof said biasing means, said relative movement between said relativelymovable contact and supporting arm causing rolling movement between saidrelatively movable and stationary contacts from a point of initialengagement to a point of iinal engagement.

l2. In a switch, a relatively stationary contact, a relatively movablecontact having a tip with a curved surface, said curved surface having apoint of initial engagement with said stationary contact and anotherpoint of final engagement upon actuation of said movable contact towardsaid stationary contact, a contact supporting arm, means for pivotallymounting said movable contact on said supporting arm, said tip being onone side of said pivot, said contact having a stop cooperable with saidarm on the other side of said pivot, spring means operatively connectedto said relatively movable contact and said arm between said pivot andsaid stop for biasing said stop against said arm, means for moving saidarm and pivot to cause said relatively movable contact to move therewithuntil initial engagement is made between said tip and said stationarycontact, continuation of movement of said arm causing said contact stopto move away from said arm and movement of said relatively movablecontact relative to said arm about said pivot against the force of saidbiasing means in order to cause rolling of said tip on said stationarycontact until the position of nnal engagement obtains.

13. In a switch, a relatively stationary contact, a contact supportingarm, a relatively movable contact pivotally mounted on said arm andhaving a tip with a curved surface on one side of said pivot, saidcurved surface and said stationary contact having a point of initialengagement and another point of final engagement upon actuation of saidmovable contact toward said stationary contact, said relatively movablecontact having an end remote from said tip extending on the oppositeside of the pivot, said extension being of such size relative to thecontact tip that the center of gravity of said relatively movablecontact is between said end and said pivot, spring means operativelyconnected to said relatively movable contact and said arm and betweensaid end and the pivot for biasing said end in engagement with said arm,means for moving said arm and pivot to cause said relatively movablecontact to move therewith until initial engagement is made between saidtip and said stationary contact, continuation of movement of said armcausing said contact end to move away from said arm and movement of saidrelatively movable contact relative to said arm about said pivot againstthe force oi said biasing means in order to cause rolling of said tip onsaid stationary contact until the position of nal engagement obtains.

14. In a switch, a relatively stationary contact, a contact supportingarm having a pivot, a relatively movable contact pivotally mounted onsaid arm and having a tip with a curved surface on one side of saidpivot, said curved surface and said stationary contact having a point ofinitial engagement and another' point of nal engagement upon actuationof said movable contact toward said stationary contact, said contacthaving an end remote from said tip extending on the opposite side ofsaid pivot, said extension being of such size relative to' the contacttip that th'e center of gravity of said relatively movable contact isbetween said end and said pivot, spring means operatively connected tosaid contact and said arm and between said end and the pivot for biasingsaid end into engagement with said arm, means for rotatably mountingsaid contact supporting arm about an axis perpendicular to itslongitudinal axis, means for rotating said arm about its rotational axisto cause said contact to move therewith until initial engagement is madebetween said tip and said stationary contact, continuation of movementof said arm causing said contact end to move away from said arm andmovement of said relatively movable contact relative to said arm aboutsaid pivot against the force of said biasing means in order to causerolling of' said tip on said stationary contact until the position offinal engagement obtains.

15. In a, switch, a relatively stationary contact, a contact supportingarm, a relatively movable Contact pivotally mounted on said arm andhaving a tip with a curved surface on one side of said pivot, saidcurved surface and said stationary contact having a point of initialengagement and another point of nal engagement upon actuation of saidmovable contact toward said stationary contact, said contact having anend remote from said tip extending on the opposite side of the pivot,said extension being of such size relative to the contact tip that thecenter of gravity of said relatively movable contact is between said endand said pivot, rod means having one end connected to said contact at apoint between said end and said pivot and extending throughsubstantially aligned apertures in said movable contact and said arm,spring means compressed between said arm and the other end of said rodmeans for biasing said end of said contact into engagement with saidarm, means for moving said arm and pivot to cause said contact to movetherewith until initial engagement is made between said tip and saidstationary contact, continuation of movement of said arm causing saidcontact end to move away from said arm and movement of said relativelymovable contact relative to said arm about said pivot against the forceof said biasing means in order to cause rolling of said tip on saidstationary contact until the position of iinal engagement obtains.

i6. In a switch, a plurality of pairs of relatively movable contacts,actuating means including an operating arm movable in a first or asecond direction for actuating a first or a second of said pairs oiccontacts respectively, a locking means including a rotatably mountedlocking plate and two rotatably mounted dogs, said locking plate havinga slot, one of said dogs having a pin adapted to nt into said slot and astop portion, spring means biasing said one of said dogs so that saidstop portion is in the path of movement of said operating arm so as toprevent movement thereof in a first direction, means for moving saidlocking plate to a seco-nd position so as to move said dog out of thepath of movement of said operating arm so that said arm may move in saidfirst direction, said second dog being movable into the path of movementof said arm when said plate has been moved to said second position so asto prevent movement of said arm in said second direction.

17. In a switch having relatively movable contacts, means for actuatingsaid contacts and movable in a first or in a second direction, lockingmeans including a dog biased to a position to prevent movement lof saidactuating means in said first direction, a locking plate having a slot,said dog having a pin adapted to l'it into said slot, said locking platebeing movable so as to cause movement of said dog to a second positionthrough said pin and siot connection, said dog When in said secondposition being out of the path of movement of said actuating means sothat said actuating means is movable in said first direction.

18. In a switch having relatively movable contacts, means for actuatingsaid contacts and movable in a rst or in a second direction, lockingmeans including a pair of movably mounted spaced dogs, one of said dogsbeing biased to a position to prevent movement of said actuating meansin said first direction, said other of said dogs being biased to aposition to prevent movement of said actuating means in said seconddirection, means cooperable with said dogs and when in one positionadapted to retain said second dog out of the path of movement of saidactuating means, said last-mentioned means being adapted to be moved toa second position to retain said first dog out of the path of movementof said actuating means and to allow said second dog to move into thepath of movement to prevent movement of said actuating means in saidsecond direction.

19. In a switch having relatively movable contacts, means including aContact positioning arm and an operating arm for actuating saidcontacts, an oncle-sing casing, a supporting plate, means for mountingsaid supporting plate in said enclosing casing, means for movablymounting said positioning arm on said supporting plate, means includinga shaft extending through an aperture in said casing for pivotallymounting said operating arm within said casing, an operating handleattached to the end of said shaft extending through said aperture, and apin and slot connection between said operating arm and positioning armso that the latter is movable to actuate said contacts upon movement ofthe former and so that said supporting member may be removed from saidcasing upon disassembly thereof from said casing without removing saidpositioning arm from said shaft.

20. In a switch, an insulating base, a contact, a Contact stud havingone end connected to said contact and the other end extending from saidbase, a line stud adapted to be connected to a line and extending in adirection perpendicular to said contact stud, a removable busbar forconnecting said contact stud to said line stud, said studs havinglocknuts threaded thereon for tightly holding said busbars to saidstuds, and U- shaped slots in said busbar in the portions thereof whichmake contact with said studs so that loosening of said nuts from saidbusbars will allow said busbars to be removed from said studs throughsaid U-shaped slots.

21. In a switch, a rst pair of relatively movable contacts, a secondpair of relatively movable contacts, means movable from the neutralposition to a iirst position for actuating said rst pair of contacts andmovable to a second position for actuating said second pair of contacts,and locking means cooperable with said actuating means and movable froma rst to a second position, said locking means when in its rst positionallowing said actuating means to move from its neutral position to itsfirst position but preventing movement to its second position, saidlocking means when in its second position allowing movement of saidactuating means from said neutral to said second position but preventingmovement to its rst position.

22. In a switch, a plurality of pairs of relatively movable contacts,means movable from a neutral to a first or to a second position foractuating a rst or a second oi said pairs of contacts respectively,locking means cooperable with said actuating means and movable from aiirst to a second position, said locking means when in its firstposition preventing movement of said actuating means to its secondposition, removable key means insertable in the switch for moving saidlocking mechanism to said second position for allowing said actuatingmeans to move to its second position, and means for preventing theremoval of said key means with said locking means in said secondposition.

WILLIAM V. HONEY.

